The fact that the present composition forms a RELATIVELY TOUGH, SELF-SUPPORTING TOPICALLY ADHERENT ANTIBACTERIAL FILM ON THE ANIMAL is a particularly novel and unobvious feature of the present invention and is completely unsuggested by prior available veterinary topical antibacterials and teat dips. Many prior patents, as discussed herein below, have interpreted the formation of a gummy, sticky surface residue on the animal as a membrane. By contrast, the protective membrane formed by the present composition is a relatively tough, self-supporting membrane which, under actual field use conditions, can be peeled away from the animal as a self-supporting membrane similar to a sheet of polyplastic.
Certain other patents (as described herein below) have disclosed the use of latex to form a protective barrier in topical antibacterials. However, such latex-based compositions must be manually peeled from the animal at removal time. Also, latex-based teat dips leave non-water soluble latex residues which clog the in-line filters of milk collecting equipment. By contrast, the protective membrane formed by the present composition, while being relatively tough and self-supporting, is also easily and completely removed from the animal by simple water washing.
These film-forming advantages, as well as other novel and unobvious advantages of the present topical antibacterial, will be described in greater detail further herein.
Animals are known to be particularly susceptible to various topical bacterial infections and inflammations due to the high bacterial count of their environments. Ruminant dairy animals are especially susceptible to infections and inflammations of the udder, known as bovine mastitis, in intensive milk producing operations. Effective application of antibacterial formulations to animals requires that the formulation remain adherently in contact with the affected area. Antibacterial teat dip application is an important regimen in effective dairy herd management, and it is recognized that a teat dip's effectiveness requires that it remain in contact with the animals' teats and udders between milkings, but be readily and completely removable by simple washing at the next milking time.
A variety of topical veterinary antibacterials, including those for teat dip applications are known, as described in some of the following United States patents. U.S. Pat. No. 4,012,504 describes a solution of iodine in mineral oil. U.S. Pat. No. 4,017,408 describes a water soluble liquid concentrate of iodine, dimethyl sulfoxide and a liquid detergent. U.S. Pat. No. 4,271,149 describes iodine-containing compositions in which iodine levels are maintained by the presence of iodide and iodate. U.S. Pat. No. 4,049,830 describes a pH controlled oil-in-water teat dip including bronopol and certain lipids. U.S. Pat. No. 4,199,602 describes neutral to mildly acidic teat dips based on anti-microbial nitroalkanols potentiated with an aminocarboxylic-type chelating agent.
U.S. Pat. No. 4,258,056 describes teat dips similar to those of U.S. Pat. No. 4,199,602 and including an anionic surfactant. U.S. Pat. No. 4,434,181 describes a composition comprising a cellulosic water soluble film former and chlorhexidine in a freeze-resistant volatile solvent. U.S. Pat. No. 3,993,777 utilizes quaternary annonium surfactant germicides in conjunction with certain emollients. U.S. Pat. No. 4,376,787 uses acidic pH controlled anionic surfactant compositions.
U.S. Pat. No. 4,199,564 describes an aqueous tincture of a lower alkanol microbicide, a film-forming polymer and an emollient. U.S. Pat. No. 4,446,153 describes a composition of a phenyl alkanol, a surfactant emulsifier and an optional emollient, controlled to a normal to mildly acidic pH. U.S. Pat. No. 4,401,666 describes a teat dip using a metallic salt of pyridine-2-thione-N-oxide. U.S. Pat. No. 4,610,993 describes a teat dip using 2,2'-dithiobis-pyridine 1,1'-dioxide and adducts thereof. U.S. Pat. No. 4,067,997 discloses certain phenolic compounds, such as resorcinol compounds, to be the antimicrobicide in a claimed synergistic combination with a non-ionic surfactant and a polyol.
A chlorinated cyanurate provides the active ingredient in the powdered, water-dispersible formulation of U.S. Pat. No. 4,025,628. A bis[4-(amino)-1- pyridinium]alkane salt is the antimicrobial agent in the teat dips of U.S. Pat. No. 4,542,125. In the teat dips of U.S. Pat. No. 4,311,709, the antimicrobially active ingredient is a loweralkyl substituted diphenyl polyamine.
Prophylactic treatment of mastitis is taught by the use of film-forming teat coating dips which physically entrap the bacteria, as in U.S. Pat. No. 4,113,854 (an aqueous medium containing a polymer latex and a water soluble polymer thickening agent), U.S. Pat. No. 4,344,967 (an aqueous solution of a protein hydrolystate, glycerol and optionally a water-miscible solvent), and U.S. Pat. No. 4,584,192 (a copolymer of certain monomeric substituted acrylic acid esters with N-vinyl lactam). It is often suggested to include antimicrobials in these compositions to achieve maximum effectiveness.
It has recently been found to be important to avoid the use of antibiotics, such as those generally used in the above mentioned veterinary antibacterials and teat dips, for a number of reasons. Continual use of such products can result in the antibiotics accumulating in the animals' milk supply to a level where they become a source of contamination, rendering the milk unfit for human consumption. Also, the excessive use of antibiotics in veterinary medicine apparently contributes to the development of resistant strains of bacteria, which may be a source of both animal and human diseases.
Accordingly, it has been considered desirable in veterinary use, especially in the dairy industry, to develop an effective antibacterial and teat dip which avoids the use of conventional antibiotics. Thus, in U.S. Pat. No. 4,545,351, a liquid adherent teat dip composition is provided which avoids the use of such conventional antibiotics, comprising an aqueous acidic suspension of a coagulated casein, solubilized by an aliphatic sulfate detergent and optionally glycerin and lactobacillus-elaborated antibiotic-like factors.
It is further important that a veterinary topical antibacterial and teat dip be available that is comprised of ingredients which are food grade, innocuous and non-irritating as possible to both the animals and the humans who come in contact with it, while also maintaining a high level of antimicrobia effectiveness in the prevention, control and treatment of bovine mastitis. It is particularly important that a teat dip be available which is effective against gram negative bacterial pathogens, such as Escherichia coli, which are a primary source of veterinary infections such as bovine mastitis. Most teat dips currently available are not effective against gram negative bacterial pathogens. Additionally, an effective teat dip should satisfy the other criteria previously described above.